This is a giant power supply in a building that I used to work in. The “supplies” side is still connected and functional, except for one sticky potentiometer. The “distribution” side has been disconnected. Unfortunately, the system’s primary function now is that of a storage cabinet. I am not sure of what the rectifiers are, they really put out a great waveform. This is from the 1960’s era. I will try to get a picture of the back the next time I’m there.

I knew panels like this. My high school had them, both in the electrical shop (where they were actually used), and in the science classrooms, where they were just there.

At each desk was a plate with an assortment of terminals, and a 120V AC duplex.

I forget the minute details, but think that you'd jumper from the distribution terminals to the bus terminals in the middle, which connected to the supplies.

It seems that the pictures setup does 12 desk stations with 3+2 terminals, and possibly 120V AC, with the breakers for those along the bottom of the supply panel, the big switch on the lower left being the main.

Yes, this is in a school. you are all spot on. You would use patch cables to go from the supplies to the desks. Each desk had a pair of 14awg wires, a pair of 12 awg wires, and a 20 amp cct. going to it. There was also some funky control wiring with this. At one point, that breaker in the far left was the main, which is why it has shoe marks on it, from people having turned it on/off with their feet. The whole thing was wired to a 70 amp, 3 phase 480 volt breaker. It is still connected, (mostly) although it is used very rarely now, mostly for things that require very high current. The 300VDC supply can only put out 10 amps, but the 50VDC one can put out 50. I can't remember what the third one is. This also had a variable AC supply, but I can't remember the ratings of it.

Ahhh ya my highschool had one of them as well! It was similar but not exact and yes it was made by " Hampden".. I remember our electricty teacher had me make a few changes to the classroom and a lot of them required work in the back of our panel... I wish I had pictures of it. A.D

We have about 10 of these exact panels in use every day. The Science building on my campus uses them for projects. They are fed from a 120/208 3 phase 50 amp breaker. Once in a great while a pot or power supply needs tweaking and out electronices techs take care of that. Ours also have a terminal for high frequency but I don't think that's worked in the 20 years I've been on campus.